1. Field of the Invention
The present invention relates to a linear compressor, and more particularly to a linear compressor that is capable of successively compressing a fluid with a plurality of compression chambers before the fluid is discharged.
2. Description of the Related Art
Generally, a linear compressor is constructed such that a linear driving force from a linear motor is transmitted to a piston, which is linearly reciprocated in a cylinder, whereby a fluid, such as coolant gas, is introduced, compressed, and discharged.
FIG. 1 is a longitudinal sectional view showing a conventional linear compressor.
As shown in FIG. 1, the conventional linear compressor includes an inner case 10 mounted inside a hermetically sealed container 1. The inner case 10 is formed in the shape of a cylinder having a prescribed length. To one side of the inner case 10 is fixed a back cover 20 having a fluid inlet channel 18 formed therein.
Inside the inner case 10 is mounted a linear motor 30 for generating a driving force. To the linear motor 30 is connected a piston 40 having a fluid flow channel 38 formed therein. To the piston is attached an inlet valve 50 for opening and closing the fluid flow channel 38. To the other side of the inner case 10 is fixed a cylinder block 60 having a cylinder 58, in which the piston 40 is movably fitted such that the piston 40 can be moved forward and backward in the cylinder 58.
To the cylinder block 60 is attached an outlet valve 70 for opening the cylinder 58 so that the compressed fluid is discharged and for closing the cylinder 58 so that the compressed fluid is not discharged. The outlet valve 70 defines a compression chamber C together with the cylinder 58 and the piston 40.
To the hermetically sealed container 1 is connected an inlet connection pipe 2, through which a fluid is introduced into the hermetically sealed container 1 from the outside, in such a manner that the inlet connection pipe 2 is disposed in front of the fluid inlet channel 18 of the back cover 20.
The inlet valve 50 is formed in the shape of a plate. One side of the plate is fixed to the piston 40, and the plate is elastically bent for opening and closing the fluid flow channel 38 of the piston 40.
The outlet valve 70 comprises: an outlet cover 72 mounted to the cylinder block 60 and connected to an outlet pipe at one side thereof; and a valve body 76 supported by a spring 74 disposed in the outlet cover 72 for opening and closing the cylinder.
The operation of the conventional linear compressor with the above-stated construction will now be described.
When electric current is supplied to the linear motor 30, the linear motor 30 is operated so that the piston 40 is linearly reciprocated in the cylinder 58. As the piston 40 is linearly reciprocated in the cylinder 58, the outlet valve 70 and the inlet valve 50 are opened and closed.
At this time, the fluid is introduced into the hermetically sealed container 1 through the inlet pipe 2. Subsequently, the fluid is guided into the compression chamber C through the fluid inlet channel 18 of the back cover 20 and the fluid flow channel 38 of the piston 40. The fluid introduced into the compression chamber C is compressed by the linear reciprocating movement of the piston 40. The compressed high-temperature and high-pressure gaseous fluid is discharged out of the hermetically sealed container 1 through the outlet valve 70 and the outlet pipe.
However, the above-mentioned conventional linear compressor has only a single compression chamber disposed in the cylinder block with the result that the fluid introduced into the compressor is compressed only once in the compression chamber C formed between the piston 40 and the outlet valve 70, and is then discharged. Consequently, the conventional linear compressor has problems in that compression efficiency of the linear compressor is very low, and performance of the linear compressor is limited.